• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Quantum Beam Science >The First Two Decades of Neutron Scattering at the Chalk River Laboratories
【24h】

The First Two Decades of Neutron Scattering at the Chalk River Laboratories

机译：在粉河实验室的前二十年中子散射

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The early advances in neutron scattering at the Chalk River Laboratories of Atomic Energy of Canada are recorded. From initial nuclear physics measurements at the National Research Experimental (NRX) reactor came the realization that, with the flux available and improvements in monochromator technology, direct measurements of the normal modes of vibrations of solids and the structure and dynamics of liquids would be feasible. With further flux increases at the National Research Universal (NRU) reactor, the development of the triple-axis crystal spectrometer, and the invention of the constant-Q technique, the fields of lattice dynamics and magnetism and their interpretation in terms of the long-range forces between atoms and exchange interactions between spins took a major step forward. Experiments were performed over a seven-year period on simple metals such as potassium, complex metals such as lead, transition metals, semiconductors, and alkali halides. These were analyzed in terms of the atomic forces and demonstrated the long-range nature of the forces. The first measurements of spin wave excitations, in magnetite and in the 3D metal alloy CoFe, also came in this period. The first numerical estimates of the superfluid fraction of liquid helium II came from extensive measurements of the phonon–roton and multiphonon parts of the inelastic scattering. After the first two decades, neutron experiments continued at Chalk River until the shut-down of the NRU reactor in 2018 and the disbanding of the neutron effort in 2019, seventy years after the first experiments.
机译：记录了加拿大粉河实验室中子散射的早期进展。从国家研究实验（NRX）反应堆的初始核物理测量来实现的是，通过可用的助焊剂和单色仪技术的改进，直接测量固体振动的正常模式和液体的结构和动态即可是可行的。通过进一步的助焊剂在国家研究通用（NRU）反应器中增加，三轴晶体谱仪的开发，以及恒定Q技术的发明，晶格动力学和磁性的领域及其在长期方面的解释及其解释原子之间的范围力和旋转之间的交换相互作用前进。在七年内对钾，复合金属如铅，过渡金属，半导体和碱卤化物进行七年期进行实验。这些在原子力方面分析并证明了力的远程性质。在此期间，磁铁矿和3D金属合金Cofe中的旋转波激发的第一次测量也在此期间。液氦II超流体分数的第一数值估计来自大声测量的旋转旋转和非弹性散射的多光部分。前二十年后，中子实验继续在粉笔河上继续，直到2018年的NRU反应器的关闭以及2019年的中子努力的解散，七十年后第一次实验。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号